Various types of construction and mining machinery, such as tractors, backhoes, excavators, motor graders, and wheel loaders, commonly include linkage pin joints that allow for adjacent members of a linkage to pivot or rotate with respect to one another. The pins are commonly cylindrical in shape and, in some applications, are made from hardened steel. The pins are disposed through a pin joint where the two adjacent linkage members meet and provide a cylindrical bearing surface around which the members pivot.
Sleeve bearings are commonly disposed within the pin joints to provide an interior bearing surface between the linkage members and the pin. The sleeve bearings are frequently tubular in shape and can be press fit into the joints or secured by other suitable mechanisms. As the adjacent members of a linkage pivot with respect to one another, the pin's outer bearing surface bears against the inner surface of the sleeve bearing. It is important to keep the interface between the pin and the inner surface of the sleeve bearing well lubricated to limit part wear and the need for replacement parts.
U.S. Pat. No. 1,746,020 (“the '020 patent”) describes one example of a bearing with recesses formed into the interior. More specifically, the '020 patent describes a bearing with recesses that have arcuate shaped bottoms and are aligned along with the rotation of a shaft disposed within the bearing. The bearing arrangement described in the '020 patent as well as in other bearings with interior recesses results in relatively high contact stresses concentrated at sharp corners of the recesses. Additionally, bearings like those described above often lack adequate balance of contact stresses, load distribution, and bearing support. This can result in increased wear rates resulting in frequent part replacement.
The inventors have created this background description to aid the reader and not to indicate that any of the indicated problems were themselves appreciated in the art. While the principles described in the disclosure can, in some respects and embodiments, alleviate the problems inherent in other systems, the scope of the invention is defined by the attached claims, and not by the ability of any disclosed feature to solve any specific problem noted herein.